Question

Discuss the significance of displacement current and find the phase difference between it and the conduction current. 
 

Hint:

In capacitive circuits with AC, the displacement current plays an important role in continuity by balancing the conduction current.

Answer 1

- Displacement current: Displacement current is the current that appears to flow in the space between the plates of a capacitor when the electric field between the plates is changing. It was introduced by Maxwell to account for the continuity equation in varying electric fields. The displacement current \( I_d \) is related to the rate of change of the electric flux \( \Phi_E \) as: \[ I_d = \varepsilon_0 \frac{d\Phi_E}{dt} = \varepsilon_0 A \frac{dE}{dt}, \] where \( A \) is the area of the plates, and \( E \) is the electric field. - Phase difference between displacement current and conduction current: In an alternating current circuit involving a capacitor, the conduction current and the displacement current are in phase. This means the peak values occur at the same time, resulting in no phase difference.